Yama-Whata? Decoding Wetsuit Jargon

By Aaron Hersh

Published Jun 3, 2014

Photo: John David Becker

Decode wetsuit jargon—and find the best suit for your needs—with this guide to neoprene lingo.

Fit is king, but the composition of a wetsuit also has a big impact on comfort, speed and value. Many wetsuits have more badges describing their features than a NASCAR vehicle has sponsor logos, and deciphering the buzzwords is no easy task. We talked to the source—the Yamamoto Corporation, a factory that produces suits for many brands across the sport—to find out how the different terms translate once you get in the water.

Ignore the whiz-bang names invented by marketing departments; these are the three core attributes that make the backbone of a suit.

Rubber type

Yamamoto uses numbers to name popular neoprenes. Knowing the differences can help you select the suit that best matches your preferences: 38, 39 and 40 are some of the most commonly used materials in wetsuits and all three have distinct characteristics.
Yamamoto 38
What you get: Good buoyancy, durability at a low price
What you don’t: Flexibility

Used in many low- to mid-priced suits, 38 is just as buoyant as the much pricier 40, but requires 22 percent more force to stretch the rubber by half its length. The result is a stiffer, more constrictive feel.

Yamamoto 39
What you get: Best buoyancy, easiest flexibility
What you don’t: Durability

This mid-priced material is actually the most flexible in the Yamamoto line, requiring 8 percent less force than 40 to lengthen by half. It’s also a whopping 24 percent more buoyant than 38 and 40.

Yamamoto 40
What you get: Moderate durability and buoyancy; potential for elite flexibility
What you don’t: Low price or best-in-class performance in any category

Equal-sized panels of 40 are slightly less flexible than 39, but the toughness of 40 makes it the material of choice for extremely thin panels across areas such as the back and shoulders. Paper-thin panels make for a suit that is dramatically easier to stretch. Price is the drawback.

Neoprene thickness

Regardless of the material used, neoprene thickness is extremely important. A 4mm-thick panel will be half as flexible as 2mm worth of the same material. This has an especially noticeable effect on the back, arms, shoulders and underarm of a suit where it stretches most during a stroke.

Inner Liner

Hidden inside is one of the most important and often overlooked parts of a wetsuit. A thin layer of polyester or nylon fabric is used to bolster every wetsuit, and this component has a major impact on flexibility. The most flexible version used by Yamamoto can stretch more than 70 percent farther than the least elastic option. If you want a free-moving suit that doesn’t feel constricting, pay as much attention to the jersey as you would to the neoprene. Softer feeling materials with tiny loops of thread coming off the neoprene tend to be most flexible.

Beyond Buoyant

Notice dimples across the surface of a suit? That is Aerodome, a material made by sandwiching sheets of neoprene together with air pockets in the middle layer. Orca claims its version increases buoyancy by 30 percent over Yamamoto’s most buoyant standard neoprene, 39.

Find your match

Not all wetsuits are designed with the same goals in mind. Some compress the torso to streamline the swimmer and reduce drag, which others are created for maximum freedom of movement. Decide what you value most—speed or comfort—and find a suit that meets your needs. It might not be the most expensive one. Take them to the water to find out.